Adjustable height chair arm



FIG. 1 is a front prespective view of an adjustable height chair arm, showing my new design; the broken lines are for environmental purposes only and form no part of the claimed design;

FIG. 2 is a right side elevational view thereof;

FIG. 3 is a front elevational view thereof;

FIG. 4 is a rear elevational view thereof;

FIG. 5 is a Left elevational view thereof;

FIG. 6 is a top elevational view thereof; and,

FIG. 7 is a bottom elevational view thereof. 

The ornamental design for an adjustable height chair arm, as shown and described. 